Article supporting rack



April 1953 G. J. ESSEFF ETAL ARTICLE SUPPORTING RACK Filed 001;. 14,1955 INVENTOBS GEd. [SSEFF URC'E United Sitates Patent 2,831,808 ARTICLESUPPORTING RACK George J. Esseif, Fort Belvoir, Va., Sidney Levine,Washington, D. C., and Woodrow Thurston, Fort Belvoir,

Application October 14, 1955, Serial No. 540,656 5 Claims. (Cl. 204-297)(Granted under Title 35, U. S. Code (1952), sec. 266) The inventiondescribed herein may be manufactured and used by or for the Governmentfor governmental purposes without the payment of any royalty thereon.

This invention relates to an article supporting rack and moreparticularly to a rack for supporting articles in an electrolytic bathin an anodic oxidation process, as in an electroplating process or thelike.

In an anodic oxidation process, the article to be anodized is submittedto an electric current while immersed in an electrolytic fluid wherebyan ionic transference causes an even coating to be deposited on theexposed surfaces of the article. One important consideration in this andrelated processes is that an unrestricted flow of electrolyte bepermitted around the whole of the article upon which the transference isto take place. This is so whether the article is to be coated with aninsulating oxide as in the anodic oxidation process, or with a metalliccoat as in the electroplating process, or where the article is to betreated chemically in the absence of an electric current. Implicit inthis problem is the consideration of contact areas. In all suchprocesses, the article to be worked upon must in some way be suspendedin the fluid. Obviously, where physical means of suspension or supportare used, there will be areas on the article which will not come incontact with the fluid. In an anodic oxidation process or electroplatingprocess these areas of contact are generally identical with the areas ofelectrical contact as well as areas of support or suspension. At thepoint where the flow of current passes to the article, no oxidation ortransference takes place. It is therefore desirable in such processesthat these areas be as small as possible and in non-critical locations.At the same time, in processes involving electricity, good contact isessential for complete success. The problem then resolves itself intoobtaining maximum electrical contact and support for the article with aminimum of unexposed surface area. Generally, the rack is electricallyconductive and transmits the current to the held article at contactpoints. These contact points in an anodic oxidation process eventuallybecome unusable and require replacement because the oxide coating formedis an eifec tive insulator and as the points themselves become coated,the necessary flow of current is diminished. Accordingly, it isdesirable to be able to remove and replace such contact points easilyand inexpensively. The rack itself in an anodic oxidation process willalso become coated with oxide. Where it is constructed of aluminum,magnesium or the like, it is stripped of such oxide prior to re-use bydipping it in an alkali bath as is well-known in the art. Where the rackis constructed of titanium, the slight oxide film that forms does notmaterially effect the operation of the anodic oxidation process and therack and associated parts can be re-used time after time with outstripping. Where different shapes and sizes of articles to be workedupon are contemplated, the problems of immersion, good current flow(where applicable), and minimum contact area are multiplied.

moval-and inexpensive replacement of the contact points as necessary.

A further object is to provide support means which can also be used aselectrical contacts where needed.

A further object is to provide support means which assure adequatespacing between the rack and the article to be treated.

A further object is to allow complete encompassing of through the use ofthe article to be treated by the fluid the open frame structure of therack.

A further object is to provide adjustable contact and'.

support means so that the inevitable bare spots on the treated articlecan be localized to predetermined noncritical areas.

A further object of this invention is to minimize thesize of the contactareas and at the same time assures good electrical contact wherenecessary between the rack and the treated article.

Following is a more which Fig. 1 isa perspective view of the rack shownsus-- pended in a bath and supporting an article to be treated;

Fig. 2 is a vertical longitudinal section on the line 2-2.

of Fig. 1;

Fig. 3 is a transverse section on 1, showing the head of a theinterconnecting slots Fig. 4 is a transverse 1, showing the heads of thecontact pins in relation to the flange openings whereby easy insertionand removal. of the pins into the frame is effected; and

Fig. 5 is an enlarged View of the contact pin assembly, showing therelative positions of the head, threaded base, locking collar, shank,and locking nut.

The rack shown in Fig. 1 is especially adapted for supporting articlesin a standard anodizing bath, such as a solution of sulphuric, chromicor other acid. It is shown of the frame;

connected to an electrical source through conductors 16 v and suspendedin-a tank 14 for containing an electrolytic bath with a cathode 15. ofaluminum, titanium, or any light metal alloy." It consists of asuspension bar'2 and interconnecting channels 3 forming an open frame.The channels have inwardly-directed flanges 4 on a side forming slots 5.Spaced at each intersection of the channels'is an opening 6 in the sideof the flange which has sufiicient clearance for the head 7 of thecontact pin 8. As shown in Fig. 1, the head 7 of the contact pin 8 canbe inserted into the slots 5 at openings 6, and the pin moved to anypart of the frame where it can be fastened into place by the lockingcollar 9 and lock nut 10 operating in conjunction with the threadedportion 11 of the shank 12. The article 13 to be anodized or the like isheld in place variously by the pins 8 as shown in Fig. 1, where the twolower pins support the base while the two upper pins act in apincer-type relation. The contact pins 8 are constructed of anelectrically conductive material such as aluminum, titanium or any lightmetal alloy as are the locking collar 9 and lock nut 10, which areintegral parts of the contact pin unit designated generally as 8. As canbe seen, the areas of contact between the pins 8 and the article 13 arevery small yet good electrical contact is assured at predeterminedpoints.

It is to be understood that this rack would be equally eflicacious wherepurely chemical treatment of articles detailed description of theinven-- tion taken in conjunction with the appended drawings, in.

the line 33 of Fig. contact pin in position in one of section on theline 44 of Fig.

The rack 1 can be constructed was desired in the absence ofelectro-stimulation. In such a case, the rack and the pins could beconstructed of any material desired including inexpensive light-weightplastics. Moreover, the rack itself could be of any design, such as agrid, or even circular, so long as the principle of interconnectingchannels is maintained.

Having thus described our invention, what we claim as new and wish tosecure by Letters Patent is:

1. A workholder rack for supporting articles to be treated in a chemicalbathvcomprising a frame, means for supporting said frame, said framehaving a plurality of continuous interconnecting channels havinginwardlydirected mutually spaced flanges along their edges forming guideand retention tracks, a plurality of fastening members slidably mountedin said tracks, each of said fastening members having a shank elementincluding a threaded portion and terminating in an enlarged headretained in said tracks by the inwardly-directed flanges thereof, theshank elements extending outwardly through the uninterrupted spacebetween the flanges, and projecting forward of the frame for fasteningthe work away from said frame, locking collars overlying and engagingoppositely directed flanges of said tracks, lock nuts threadedly mountedon the threaded portions of said fastening members for clamping thelocking collars and e the heads of the fastening members againstopposite sides of the flanges of said tracks thereby locking thefastening members in adjusted position with respect to the frame.

2. A workholder for supporting articles to be treated in a chemical bathcomprising a frame, means for supporting said frame, said frameincluding a plurality of continuous interconnecting channels havinginwardlydirected mutually spacedflanges along their edges forming guideand retention tracks, a plurality of fastening members slidably mountedin said tracks, each said fastening member having a shank and anadjacent threaded portion terminating in an enlarged head retained insaid tracks by the inwardly-directed flanges thereof, the shank portionsextending outwardly through the uninterrupted space between the flanges,and projecting forward of the frame whereby the work may be fastened inposition away from the frame, locking collars overlying and engaging theoppositely directed flanges of said tracks, lock nuts engaging thethreaded portions of said fastening members for clamping the lockingcollars and the heads of the fastening members against said flanges forlocking the fastening members in adjusted position with respect to theframe, and a plurality of openings in said flanges for removing saidfastening me ibers from said tracks.

3. A rack for supporting a plurality of variable-shaped articles. in anelectrolytic bath comprising a frame of electrically-conductingmaterial, said frame having a plurality of continuous interconnectingchannels formed by inwardly-directed mutually spaced flanges along theiredges defining guide and retention tracks, a plurality ofarticle-supporting, electrically-conducting pins slidably mounted insaid tracks for movement to any part of the frame within theinterconnecting guide and retention tracks, each said pin including apartially threaded shank element and having an end thereof terminatingin an enlarged head, the heads of said pins being positioned in saidtracks beneath said flanges, said shank elements projecting outwardlythrough the uninterrupted spaces between the flanges for supportingvariably-shaped articles at a spaced relationship from the frame,locking collars overlying and engaging the oppositely directed flangesof said tracks, lock nuts threadably mounted on the threaded portions ofthe pins for clamping the locking collars and the heads of the pins tosaid flanges thereby locking the pins in adjusted position with respectto the frame, and means for supporting said frame.

4. A rack as recited in claim 3 wherein said flanges have a plurality ofopenings for removing said pins from said channels.

5. A rack for supporting variably-shaped articles in an electrolyticbath comprising a sectionalized frame of electrically conductivematerial, said frame formed of continuous interconnecting channelshaving inwardlydirected, mutually spaced flanges, said flanges formingan unbroken slot throughout the entire frame, a plurality ofelectrically conductive pins, each of said pins having an enlarged headriding in said interconnecting channels, a threaded portion extendingoutwardly through said unbroken slot and terminating in a shank elementprojecting outwardly from said slot, and a locking piece for saidthreaded portion for fixing the pin at any point along the unbrokenslot, said plurality of pins collectively supporting variably-shapedarticles in spaced relation from said sectionalized frame to insure goodflow of electrolytic bath solution around the articles to be plated, aplurality of openings in the channel sections to permit said enlargedheads of said pins to enter said continuous interconnecting channels,and means for supporting said frame.

References Cited in the file of this patent UNITED STATES PATENTS1,427,875 Weeks Sept. 5, 1922 1,503,396 Voigt July 29, 1924 1,534,918Claybouin Apr. 21, 1925 2,637,689 Myers May 5, 1953 FOREIGN PATENTS986,289 France July 30, 1951 549,777 Germany Apr. 14, 1932

1. A WORKHOLDER RACK FOR SUPPORTING ARTICLES TO BE TREATED IN A CHEMICALBATH COMPRISING A FRAME, MEANS FOR SUPPORTING SAID FRAME, SAID FRAMEHAVING A PLURALITY OF CONTINUOUS INTERCONNECTING CHANNELS HAVINGINWARDLYDIRECTED MUTUALLY SPACED FLANGES ALONG THEIR EDGES FORMING GUIDEAND RETENTION TRACKS, A PLURALITY OF FASTENING MEMBERS SLIDABLY MOUNTEDIN SAID TRACKS, EACH OF SAID FASTENING MEMBERS HAVING A SHANK ELEMENTINCUDING A THREADED PORTION AND TERMINATING IN N ENLARGED HEAD RETAINEDIN SAID TRACKS BY THE INWARDLY-DIRECTED FLANGES THEREOF, THE SKANKLEMENTS EXTENDING OUTWARDLY THROUGH